× Citrofortunella microcarpa
Common Name: orange calamondin 
Type: Broadleaf evergreen
Family: Rutaceae
Native Range: Garden origin
Zone: 10 to 11
Height: 10.00 to 20.00 feet
Spread: 6.00 to 10.00 feet
Bloom Time: Seasonal bloomer
Bloom Description: White
Sun: Full sun
Water: Medium
Maintenance: Low
Suggested Use: Hedge, Flowering Tree
Flower: Showy, Fragrant
Leaf: Fragrant, Evergreen
Fruit: Showy, Edible
Other: Winter Interest

Culture

Winter hardy to USDA Zones 10-11 where it is best grown in organically rich, well-drained, sandy or clay loams in full sun. Tolerates part shade, but best flowering occurs in full sun. Best with consistent and regular watering. Established trees have moderate drought tolerance. Avoid wet poorly drained soils. Plants will struggle with temperatures below 40 degrees F., and are intolerant of frost. North of USDA Zone 10, calamondin is best grown in a container which is overwintered indoors. Use a loose, all-purpose, well-drained potting mix. Set containers outdoors in late spring in full sun in a location protected from wind. Bring containers indoors in fall for overwintering to a cool but bright sunny southern window. In winter, mist plants with water or use a humidifier (plants love humid environments). Propagate by seed or cuttings.

Noteworthy Characteristics

X Citrofortunella microcarpa, commonly known as calamondin or orange calamondin, is a small, bushy, evergreen tree or shrub which probably originates from China or the Philippines. It is believed to be a cross between Citrus reticulata (mandarin) and Fortunella japonica (kumquat). The "X" preceding the genus name indicates that this hybrid is between plants of different genuses (bi-generic hybrid). Outdoors it is grown in the ground in southern Florida, southern Texas, California and Hawaii where frost is not a concern. North of USDA Zone 10, it is grown in containers which are brought indoors in fall for overwintering to a bright sunny window. Calamondin is primarily grown in the U.S. as an ornamental. It is commercially grown in the Philippines, tropical Asia and parts of Latin America where the edible fruit is commonly consumed as a food. Calamondin is a small tree or shrub to 6-20' tall (smaller when grown in containers as houseplants). It produces a thin-skinned, juicy, golf-ball sized orange fruit (1 1/2" diameter) which is edible but the pulp and juice are very acidic (sour). The peel is sweet. Fruit remains on the plant for a long time (takes up to one year for fruit to ripen to orange). Each fruit contains 6-9 fleshy segments. Fragrant white 5-petaled flowers bloom primarily in spring, but basically may produce 4-5 smaller flushes throughout the year. Seeing flowers and ripe fruit on the plant at the same time is not unusual. Branches (sometimes with small number of short spines) are clad with oval, rich, slightly glossy, evergreen green leaves (to 2-4" long). Leaves are aromatic.

Genus name is a combination of the genus names Citrus and Fortunella.

Specific epithet means small fruit.

Problems

No serious insect or disease problems. Susceptible to Mediterranean and Caribbean fruit flies (Florida problem in particular). Aphids, spider mites, mealybugs, scale and citrus bark borers. Potential diseases include leaf mottling and citrus canker.

Garden Uses

Outdoors it is ornamentally attractive around homes or patios. May be grown as a hedge. Indoors, it serves as an excellent houseplant featuring fragrant white flowers and small orange fruits. Fruit is very sour but has a large number of culinary uses including juice added to beverages, food flavoring, sauces, marmalades, pies, and soups. Commercially grown in Asia.